Add search alias for Palembang (Musi)

Bug: T364291
Change-Id: I6514e446a6b2e5cb85dc8654942a00406127801f

data/LanguageNameIndexer.php

@@ -113,6 +113,11 @@ class LanguageNameIndexer extends Maintenance {
 			'ja' => [ 'nihongo', 'にほんご' ],
 			// Mon, renamed in core MediaWiki's Names.php (T352776)
 			'mnw' => [ 'ဘာသာ မန်' ],
+			// Palembang, also known as "Musi".
+			// Writing this as two words ensures that it has a unique key,
+			// so that Moore (mos), which is known as "musi" in one of the languages,
+			// can also be found
+			'mui' => [ 'musi palembang' ],
 			// Western Punjabi, doesn't start with the word "Punjabi" in any language
 			'pnb' => [ 'punjabi western' ],
 			// Simplified and Traditional Chinese, because zh-hans and zh-hant

data/LanguageNameSearchData.php

@@ -20808,6 +20808,7 @@ class LanguageNameSearchData {
 				'muscogeera' => 'mus',
 				'muse krií lángwej' => 'crm',
 				'musi' => 'mos',
+				'musi palembang' => 'mui',
 				'muskogee' => 'mus',
 				'muskogee-schpraach' => 'mus',
 				'muskogee-sprache' => 'mus',

tests/phpunit/LanguageSearchTest.php

@@ -76,6 +76,15 @@ class LanguageSearchTest extends PHPUnit\Framework\TestCase {
 				'pnb' => 'punjabi western'
 			]
 			],
+			[ 'musi', [
+				'mos' => 'mosi',
+				'mui' => class_exists( LanguageNames::class ) ? 'musi' : 'musi palembang',
+			]
+			],
+			[ 'palembang', [
+				'mui' => 'palembang',
+			]
+			],
 			[ 'castellano', [
 				'es' => 'castellano',
 			]